A vehicle including a chassis for supporting a rider and a wheel provided centrally on the chassis is known (See Patent Document 1). Also is known a vehicle including a pair of wheels disposed one next to the other and a step platform provided between the two wheels or on either outer side of the two wheels (See Patent Document 2) for placing the feet of a rider thereon.
Patent Document 1:
Japanese patent laid open publication No. 2004-129435 (FIGS. 39 to 42) Patent Document 2:
Japanese patent laid open publication No. 2006-008013 (FIGS. 31 to 34)